Li Hui, Chen Roland K, Tang Yong, Meurer William, Shih Albert J
Mechanical Engineering, University of Michigan, Ann Arbor, MI 48109, USA; Mechanical and Automotive Engineering, South China University of Technology, Guangzhou 510640, China; Electronic Paper Display Institute, South China Normal University, Guangzhou 510006, China.
Mechanical and Materials Engineering, Washington State University, Pullman, WA 99164-2920, USA.
J Therm Biol. 2018 Jan;71:99-111. doi: 10.1016/j.jtherbio.2017.10.022. Epub 2017 Nov 4.
Reducing brain temperature by head and neck cooling is likely to be the protective treatment for humans when subjects to sudden cardiac arrest. This study develops the experimental validation model and finite element modeling (FEM) to study the head and neck cooling separately, which can induce therapeutic hypothermia focused on the brain. Anatomically accurate geometries based on CT images of the skull and carotid artery are utilized to find the 3D geometry for FEM to analyze the temperature distributions and 3D-printing to build the physical model for experiment. The results show that FEM predicted and experimentally measured temperatures have good agreement, which can be used to predict the temporal and spatial temperature distributions of the tissue and blood during the head and neck cooling process. Effects of boundary condition, perfusion, blood flow rate, and size of cooling area are studied. For head cooling, the cooling penetration depth is greatly depending on the blood perfusion in the brain. In the normal blood flow condition, the neck internal carotid artery temperature is decreased only by about 0.13°C after 60min of hypothermia. In an ischemic (low blood flow rate) condition, such temperature can be decreased by about 1.0°C. In conclusion, decreasing the blood perfusion and metabolic reduction factor could be more beneficial to cool the core zone. The results also suggest that more SBC researches should be explored, such as the optimization of simulation and experimental models, and to perform the experiment on human subjects.
当人体发生心脏骤停时，通过头部和颈部冷却来降低脑部温度可能是一种保护性治疗方法。本研究开发了实验验证模型和有限元模型（FEM），以分别研究头部和颈部冷却，这可以诱导专注于脑部的治疗性低温。利用基于颅骨和颈动脉CT图像的解剖学精确几何形状来找到有限元模型的三维几何形状，以分析温度分布，并通过3D打印构建用于实验的物理模型。结果表明，有限元模型预测的温度与实验测量的温度具有良好的一致性，可用于预测头部和颈部冷却过程中组织和血液的时间和空间温度分布。研究了边界条件、灌注、血流速度和冷却面积大小的影响。对于头部冷却，冷却穿透深度很大程度上取决于脑部的血液灌注。在正常血流条件下，低温60分钟后，颈部颈内动脉温度仅下降约0.13°C。在缺血（低血流速度）条件下，该温度可下降约1.0°C。总之，降低血液灌注和代谢降低因子可能更有利于冷却核心区域。结果还表明，应该探索更多的亚低温治疗研究，例如优化模拟和实验模型，并在人体受试者上进行实验。
